On the equivalence between MV-algebras and ll-groups with strong unit

In "A new proof of the completeness of the Lukasiewicz axioms"} (Transactions of the American Mathematical Society, 88) C.C. Chang proved that any totally ordered $MV$-algebra $A$ was isomorphic to the segment $A \cong \Gamma(A^*, u)$ of a totally ordered $l$-group with strong unit $A^*$. This was done by the simple intuitive idea of putting denumerable copies of $A$ on top of each other (indexed by the integers). Moreover, he also show that any such group $G$ can be recovered from its segment since $G \cong \Gamma(G, u)^*$, establishing an equivalence of categories. In "Interpretation of AF $C^*$-algebras in Lukasiewicz sentential calculus" (J. Funct. Anal. Vol. 65) D. Mundici extended this result to arbitrary $MV$-algebras and $l$-groups with strong unit. He takes the representation of $A$ as a sub-direct product of chains $A_i$, and observes that $A \overset {} {\hookrightarrow} \prod_i G_i$ where $G_i = A_i^*$. Then he let $A^*$ be the $l$-subgroup generated by $A$ inside $\prod_i G_i$. He proves that this idea works, and establish an equivalence of categories in a rather elaborate way by means of his concept of good sequences and its complicated arithmetics. In this note, essentially self-contained except for Chang's result, we give a simple proof of this equivalence taking advantage directly of the arithmetics of the the product $l$-group $\prod_i G_i$, avoiding entirely the notion of good sequence.Comment: 6 page

Detector Developments for the LHC: CMS TOB Silicon Detector Modules and ATLAS TileCal Read-Out Driver

This Research Report is divided in two different parts corresponding to two different periods of time working in different collaborations. First, a general approach to the framework where this work is set is presented at the Introduction: the CERN laboratory near Geneva, the LHC accelerator and its two general purpose experiments CMS and ATLAS. The first part of this report consists in the study of the performance of the silicon strip detectors specifically designed for the Tracker Outer Barrel (TOB) of the CMS Tracker detector. Results of the performance of CMS TOB silicon detector modules mounted on the first assembled double-sided rod at CERN are presented. These results are given in terms of noise, noise occupancies, signal to noise ratios and signal efficiencies. The detector signal efficiencies and noise occupancies are also shown as a function of threshold for a particular clustering algorithm. Signal efficiencies versus noise occupancy plots as a function of the threshold level, which could also be used to grade detector modules in rods during production, are presented. In the second part the standalone software developments for the characterization and system tests of the pre-production ATLAS TileCal Read-Out Driver (ROD) prototypes are presented. The XTestROD and XFILAR programs, specifically written for the TileCal ROD characterisation and system tests, are presented and all their functionalities are discussed in detail. These programs allow to write/read the registers and configure the different operation modes of all the modules in the ROD crate and the ROS computer. Using this software standalone data acquisition runs can also be performed through the VMEbus or standard read-out cards in ATLAS

Effective theories and constraints on new phyhsics

Anomalous moments of the top quark arises from one loop corrections to the vertices $\bar t t g$ and $\bar t t \gamma$. We study these anomalous couplings in different frameworks: effective theories, Standard Model and 2HDM. We use available experimental results in order to get bounds on these anomalous couplings.Comment: 8 pages, 2 figures, talk presented by R. Martinez at the X Mexican School of Particles and Fields, Playa del Carmen, Mexico, 200

A Successful Targeted Search for Hypervelocity Stars

Hypervelocity stars (HVSs) travel with velocities so extreme that dynamical ejection from a massive black hole is their only suggested origin. Following our discovery of the first HVS, we have undertaken a dedicated survey for more HVSs in the Galactic halo and present here the resulting discovery of two new HVSs: SDSS J091301.0+305120 and SDSS J091759.5+672238, traveling with Galactic rest-frame velocities at least +558+-12 and +638+-12 km/s, respectively. Assuming the HVSs are B8 main sequence stars, they are at distances ~75 and ~55 kpc, respectively, and have travel times from the Galactic Center consistent with their lifetimes. The existence of two B8 HVSs in our 1900 deg^2 survey, combined with the Yu & Tremaine HVS rate estimates, is consistent with HVSs drawn from a standard initial mass function but inconsistent with HVS drawn from a truncated mass function like the one in the top-heavy Arches cluster. The travel times of the five currently known HVSs provide no evidence for a burst of HVSs from a major in-fall event at the Galactic Center in the last \~160 Myr.Comment: 5 pages, submitted to ApJ Letter

G 112-29 (=NLTT 18149), a Very Wide Companion to GJ 282 AB with a Common Proper Motion, Common Parallax, Common Radial Velocity and Common Age

We have made a search for common proper motion (CPM) companions to the wide binaries in the solar vicinity. We found that the binary GJ 282AB has a very distant CPM companion (NLTT 18149) at a separation s=1.09 \arcdeg. Improved spectral types and radial velocities are obtained, and ages determined for the three components. The Hipparcos trigonometric parallaxes and the new radial velocities and ages turn out to be very similar for the three stars, and provide strong evidence that they form a physical system. At a projected separation of 55733AU from GJ 282AB, NLTT 18149 ranks among the widest physical companions known.Comment: 13 pages, 3 figures, submmited to Ap